assume cs:codeseg

codeseg segment

    mov ax, 0ffffh
    mov ds, ax
    mov bx, 0h

    mov cx, 12
    mov dx, 0

add:

    mov al, [bx]
    mov ah, 0h
    add dx, ax
    inc bx
    loop add

    mov ax, 4c00h
    int 21h

codeseg ends

end